Original fgetln() from 44lite return sucess for line tail errors,

i.e. partial line, but set __SERR and errno in the same time, which
is inconsistent.
Now both OpenBSD and NetBSD return failure, i.e. no line and set error
indicators for such case, so make our fgetln() and fgetwln()
(as its wide version) compatible with the rest of *BSD.

PR:     212033
MFC after:      7 days

2 files changed, 6 insertions, 4 deletions

diff --git a/lib/libc/stdio/fgetln.c b/lib/libc/stdio/fgetln.c
index 1509bc880a4a..c8e30ee2bf65 100644
--- a/lib/libc/stdio/fgetln.c
+++ b/lib/libc/stdio/fgetln.c
@@ -139,8 +139,11 @@ fgetln(FILE *fp, size_t *lenp)
 		(void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
 		    len - off);
 		off = len;
-		if (__srefill(fp))
-			break;	/* EOF or error: return partial line */
+		if (__srefill(fp)) {
+			if (__sfeof(fp))
+				break;
+			goto error;
+		}
 		if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) == NULL)
 			continue;
 
diff --git a/lib/libc/stdio/fgetwln.c b/lib/libc/stdio/fgetwln.c
index 6a92b71ce775..34a80a076b56 100644
--- a/lib/libc/stdio/fgetwln.c
+++ b/lib/libc/stdio/fgetwln.c
@@ -53,7 +53,6 @@ fgetwln_l(FILE * __restrict fp, size_t *lenp, locale_t locale)
 	ORIENT(fp, 1);
 
 	len = 0;
-	/* WEOF or error: return partial line, see fgetln(3). */
 	while ((wc = __fgetwc(fp, locale)) != WEOF) {
 #define	GROW	512
 		if (len * sizeof(wchar_t) >= fp->_lb._size &&
@@ -65,7 +64,7 @@ fgetwln_l(FILE * __restrict fp, size_t *lenp, locale_t locale)
 		if (wc == L'\n')
 			break;
 	}
-	if (len == 0)
+	if (len == 0 || (wc == WEOF && !__sfeof(fp)))
 		goto error;
 
 	FUNLOCKFILE(fp);